The present invention relates to the control of power from a power source to voltage and/or current level sensitive electrical loads or circuits in a photographic camera, in general, and to the control of electrical power to an electronic strobe from a single internal camera power source of limited capacity when said camera is operating in a self-timer mode, in particular.
It is known in the art to control the operating sequence of an automatic self-developing camera to enable a single internal battery of limited capacity to power the camera during its entire operating cycle. U.S. Pat. No. 3,846,812, for example, discloses apparatus that operates a flash camera of the automatic self-developing type so that only one operation having a significant current drain occurs at any one time. In the camera disclosed therein, the film transport motor and the electronic flash unit draw battery current at different times during the camera operating cycle.
As shown in U.S. Pat. No. 4,472,041, it is also known in the prior art to disable the film transport mechanism of a flash camera of the self-developing type at the end of an exposure interval for the purpose of enabling the electronic flash to operate in a charging mode to thereby reduce the apparent change time subsequent to the transport of a film unit from the camera without changing the overall time required to charge the electronic flash. However, inhibiting the operation of one or more camera functions while another camera function is being performed lengthens the overall time required to complete an entire camera cycle. Camera cycle time would not be lengthened and excessive power would not be drawn from a common power source at any one time if, for example, one camera function was cycled on and off during a portion of an overall camera cycle and another camera function was actuated only during that period of time when said one camera function is in its off mode of operation.
It is a primary object of the present invention, therefore, to actuate one or more functions of a photographic camera during a normal camera operating cycle without lengthening overall camera cycle time.
It is another object of the present invention to operate one or more functions of a photographic camera, where said functions are of the type having relatively large power consuming demands such that said camera functions will neither exceed the power delivering capabilities of a power source of limited capacity nor lengthen overall camera cycle time.
It is a further object of the present invention to charge an electronic strobe during the operation of a camera's self-timer without interfering with the operation of indicators showing that the camera is operating in its self-timer mode.
Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings.